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On 16/08/2020 at 9:10 PM, CarpeDiem said:

Nice.

What battery management system / charging solution are you using? Is that per ah cost inclusive of the BMS? 

I have a BMS that was less about $90 usd and the chargers I am using have a relay control.

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If you are interested in the size differences and electrical differences of lithium Iron Phosphate and Lead Acid AGM batteries,  I have started to put my battery compartment together this weekend.

I'm very interested in this. Which brand, how are they managed, what charging system you use etc. And if all that's shipping cost, you obviously bought these overseas from somewhere, not local. W

Anyone that has charges this type of chemistry through a shunt with a coulomb counter can verify these are about 99% or more efficient.    This post was not intended to be a tutorial or a

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On 17/08/2020 at 12:51 PM, Clipper said:

I'm very interested in this. Which brand, how are they managed, what charging system you use etc.

And if all that's shipping cost, you obviously bought these overseas from somewhere, not local. Whereabouts?

These are CATL cells,  ex china.   I will be using Victron MPPT chargers, Mastervolt smart reg.

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On 17/08/2020 at 5:54 PM, MartinRF said:

Where did you get those efficiency numbers from? The reason for asking is I looked into this (for non-vehicle reasons) a few years ago and what I found then was not that high.

/Martin

 

Anyone that has charges this type of chemistry through a shunt with a coulomb counter can verify these are about 99% or more efficient. 

 

On 17/08/2020 at 10:52 PM, Island Time said:

If you are going to build your own banks, may I suggest that this is MUCH more difficult for you to get right than many believe.

It can be done, but PLEASE tread carefully! It can also fail, sometimes spectacularly, and cost you your investment, your boat, or more.

May I respectfully suggest that you START your reading here https://marinehowto.com/lifepo4-batteries-on-boats/ and do a lot of research before you commit.

This post was not intended to be a tutorial or a how to in any way.   While these batteries are far far more forgiving than most people say,  these are not drop in replacements and require a certain level of knowledge to set up and manage.   These are not set and forget and certainly not she'll be right, I know what im doing setup.      I saying all that,  I'm not sure how you would loose your boat if these failed,  you would certainly loose your pride and a large handful of cash. 

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38 minutes ago, Island Time said:

MCP, I agree these are much more stable than other forms of lithium batts, but things can still go wrong, sometimes badly. Here is an example (but not a boat) http://www.batteryvehiclesociety.org.uk/bvsorguk/forums/viewtopic.php?t=1825

 

 

Hmmm,  I suspect someone didn't fuse their wiring or some other act of stupidity near something combustible....or they actually had a cobalt/manganese variety of Lithium Ion,  which has a electrolyte that is a hydrocarbon.  The reason why companies like Tesla are moving to LiFePo4 are because they don't got into thermal run away and almost impossible to catch on fire. 

 

4 minutes ago, MartinRF said:

So the data is your own?

/Martin

 

Yes I can measure this?  Is this what you are asking?  You are being rather vague in my interpretation of your post sorry?

 

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28 minutes ago, mcp said:

....or they actually had a cobalt/manganese variety of Lithium Ion,  which has a electrolyte that is a hydrocarbon.  The reason why companies like Tesla are moving to LiFePo4 are because they don't got into thermal run away and almost impossible to catch on fire.

I read thru about 1/2 the post. His batteries were LiFeP04 cells. These cells can overheat if mismanaged. Most Electric Vehicle LiFePO4 batteries are bottom balanced. The fire occurred when he was "Equalizing"  so his charger was topping off. In this situation; a bottom balanced cell can certainly overheat and start a fire, it's a real issue and big problem, his BMS did not have temperature sensing. (and it's a bit scary that he used the word "equalizing"... not balancing

Edited by 2flit
correcting wording at mismanagement
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8 hours ago, mcp said:

Yes I can measure this?  Is this what you are asking?  You are being rather vague in my interpretation of your post sorry?

I asked for the source of the efficiency figures appearing in your first post. That was all.

/Martin

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14 hours ago, mcp said:

These are CATL cells,  ex china.   I will be using Victron MPPT chargers, Mastervolt smart reg.

Cool, Thanks.  
Am upgrade from my single 130ahr lead acid battery has been on my mind for a while, but costs have been prohibitive with local suppliers, so keep us informed on how it all goes.

 

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Ditto. Thanks, interesting.

I didn't go for firefly as is double whammy on failure,  with freight for replacement/evaluation.

Missed my chance on free freight.

Also, my R232 FLA's seem to come right back after partial state of charging for a time with 15.5v for 4hrs.

Think I will see this lot out. Toss up who will croak first.:unsure:

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